The conventional intervertebral locking device, such as the BEZAIAN SPINAL FIXATOR made by Spinal and Orthopedic Devices, Inc. of the United States, is generally composed of a rigid structure which is capable of bracing two vertebrae adjacent to a deformed vertebra in such a manner that the two vertebrae are kept apart appropriately. The bracing of the two vertebbrae by the rigid structure is attained by means of a plurality of sharp-pointed projections located respectively at the upper and the lower ends of the rigid structure. In other words, the sharp-pointed projections of the rigid structure are made use of bearing almost entirely the pressure of a patient's body exerting on the vertebrae of the patient. However, the sharp-pointed projections of the implanted rigid structure are not exerted Upon uniformly by the pressure of the patient's body in view of the fact that the vertebrae of the human spinal column have different curvatures, thereby causing the implanted rigid structure to move in a specific direction. As a result, the implanted rigid structure can not be fixed securely on the axial wheel line of the vertebrae adjacent to the vertebra under treatment. In addition, the two vertebrae adjacent to the vertebra under treatmnet are so interfered with by the implanted rigid structure that they are not so located as to form therebetween an appropriate angle.